In view of the problems of steep slope excavation,large different geological conditions and strict slope deformation control,the support and stability of high and steep slope of adjacent highway are studied.By using dynamic design method,the geological conditions such as rock formation and joint combination revealed in slope excavation are judged in real time.Combined with the safety monitoring data of slope,the support methods under different failure modes are proposed.The results show that the dynamic design of high and steep rock slope has pertinence and applicability in the case of high importance,wide range and large differences in geological and environmental conditions.It can maximize the comprehensive benefits of engineering safety,project investment and construction schedule.The relevant experience and methods can provide reference for similar projects.